[otrs] Newbie: Questions on product.

Hi all. I am just looking at OTRS for my first time and was wondering if someone can answer one question for me that the demo does not seem to answer. For my installation it is critical that when a user enters a trouble ticket, he/she should be presented with a list of categories and sub-categories which define the type of issue they are experiencing. For example; a major category would be hardware, with a sub-category of "Monitors". Is this possible with OTRS?